This invention relates generally to nucleosides and more particularly to the synthesis of purine-containing nucleosides. For example, it provides an efficient route for the synthesis of 9-.beta.-D-arabinofuranosyl adenine (hereinafter referred to as ara-A), which is an important, naturally-occurring anti-viral agent that has shown significant activity against herpes simplex and vacinia viruses in tests performed on cell cultures and on experimental animals.
One method heretofore used for the synthesis of ara-A has been the modification of preformed nucleosides, as reported in the article authored by E. J. Reist et al. appearing in the Journal of Organic Chemistry, Volume 27, Page 3274 (1962), and also in the article by M. Ikehara and Y. Ogiso, appearaing in Tetrahedron, Volume 28, Page 3695 (1972). Ara-A has also been synthesized from arabinose and its derivatives as reported in the article by C. P. J. Glaudemans and H. G. Fletcher, Jr., appearing in the Journal of Organic Chemistry, Volume 29, Page 3286 (1964) and in the article by G. Lunzmann and G. Schramm, appearing in Biochemica and Biophysica Acta, Volume 169, Page 263 (1968). However, these known syntheses have not been entirely satisfactory in that the yields were often low. New syntheses for preparing purine-containing nucleosides which can be efficiently and economically carried out using readily available starting materials are desired.